A research project at ETH Zurich is studying the process of pumping carbon dioxide into unminable coal seams and recovering the methane that is subsequently displaced.

An extensive experimental investigation about the process of desorbing methane by adsorbing carbon dioxide in real coal samples was performed. The proof of principle and the technical feasibility of the method could be verified with these measurements. These research results indicate that CBM can become an alternative to conventional natural gas. ECBM provides additional to CBM the advantage of long-term CO2 storage in the underground coal seams.[2]

However, without other incentives, enhanced coal bed methane recovery is not economical as the commercial value of the released methane does not completely offset the cost of pumping.[3]

Penetration of CO2 into coal is simulated using a stress-enhanced diffusion model.[4][5]